1. Field of the Invention
The present invention relates to an array panel, specifically, to an array panel of a liquid crystal display that a color washout problem is reduced or avoided when under a wide viewing angle.
2. Descriptions of the Related Art
With fast developing technologies, people have become accustomed to using various electronic products. One key component of multimedia electronic products is the display. Because of its desirable characteristics, such as power-saving, radiation-free, small size, low power consumption, space-saving, flat square, high resolution, and stable display quality, thin film transistor liquid crystal displays (TFT LCDs) have gradually started to replace the traditional cathode ray tube (CRT) display. Consequently, TFT LCDs are widely used as the display panel of electronic products, such as cellular phones, display screens, digital TVs, and notebooks.
Since it has started to replace CRT displays, TFT LCDS have also improved quite rapidly, especially in improving display quality. For wide viewing angles, a multi-domain vertical alignment (MVA) technique, researched by Fujitsu, extends both the upper and lower viewing angle to about 120°. This technique improves the viewing angle for the LCD substantially so that the CRT display is not the only display that has the wide viewing angle characteristic.
However, the display that employs the multi-domain alignment technique has problems involving color washout under wide viewing angles and light leakage. These complications have led to alterations in the manufacturing process, resulting in higher costs. Consequently, a polymer stabilized alignment (PSA) technique has been developed to improve the drawbacks of the multi-domain vertical alignment technique. The pixel design of the PSA technique consists of a fixed pretilt angle in each liquid crystal cell. While the pixel structure is operating, the liquid crystal cell deflects to a required angle with a shorter response time according to an electric field formed between the pixel electrode and the common electrode. Thus, multiple sub-domains are formed according to the various shapes of the pixel electrodes.
Still, due to the irregular distribution of the electric field, the neighboring liquid crystal cells of the two pixel structures are not well arranged. The neighboring liquid crystal cells of the central area of the common electrode (common line) are also not well arranged as shown in the circled area of the pixel 1 in FIG. 1. These improperly arranged liquid crystal cells leads to color washout, such that a brightness area distribution is irregular, especially for representing left and right viewing angles. Consequently, although the PSA technique has enhanced the contrast ratio and brightness, while shortening the response time for TFT LCDs, the color washout problem under a wide viewing angle still has not been resolved.
In summary, current TFT LCDs problems with color washout under wide viewing angles. In addition, the brightness area distribution is not uniform due to the irregular arrangement of the liquid crystal cells which causes light leakage and affects display quality. Consequently, there is a need to find a method to prevent color washout under wide viewing angles from occurring, as well as a need to improve the arrangement of liquid crystal cells to prevent light leakage.